JPH0110012Y2 - - Google Patents

Description

[Detailed description of the invention] This invention fits into the opening edge of a bottomed cylindrical case in which only a part of the inductor constituting the filter circuit is fixed inside, and is drawn out to the outside. This noise filter is formed by tightening the opening edge around a disc-shaped lid made of insulating material with a through hole for wires.

Conventionally, noise filters have been used, in which the circuit elements that make up the filter circuit are housed in an insulated cylindrical case made of aluminum, and the lead wire for connection to the outside is pulled out from the opening in the case. ing. In this type of filter, a lid is not used, and the casing in which the circuit elements are housed is filled with resin, which is solidified to fix the lead wires of the circuit elements.
However, a noise filter in which the lead wires are arranged and filled with a large amount of resin has the disadvantage that the lead wires are disarranged by the time the resin hardens, and a large amount of expensive resin is used.

The present invention eliminates such drawbacks of the conventional noise filter by providing a lid that fits with the opening edge of the casing, extending lead wires, and fixing circuit elements by injecting resin into a part near the bottom. The purpose is to ensure the position of the lead wire and reduce the amount of filling resin used.

That is, the present invention fixes the filter circuit element by filling only a portion of the filter circuit element with resin in a bottomed insulating cylinder 3 inscribed in a bottomed cylindrical case 2 made of aluminum, and fixing the filter element to the outside of the filter element. An inclined part 12 above the periphery having a through hole for a leader line to
In addition, a disc-shaped lid 1 made of an insulating material having a stepped portion 13 on the lower periphery is fitted into the bottomed insulating cylinder 3,
The noise filter is formed by caulking the fitting portion with the upper edge of the housing 2.

In the embodiment of the present invention, as shown in FIGS. 1a and 1b, a through hole 11 through which a lead wire is passed is formed in the center of a disc-shaped lid 1 made of an insulating material, and the upper peripheral edge of the lid 1 is formed upwardly. A sloped portion 12 with a reduced diameter, a stepped portion 13 on the lower peripheral edge, and a rod-shaped projection 14 directed downward at one location on the lower peripheral edge are provided.

Further, as shown in FIG. 2, the housing 2 has a cylindrical shape with a bottom made of aluminum, and a mounting bolt 21 is fixed to the outside of the bottom. An insulating tube 3 made of an insulating material and having a cylindrical shape with a bottom is installed inside the casing 2 . Further, a ground terminal 4 is attached to the side wall of the housing 2 and the insulating cylinder 3.

An inductor 5 is placed inside this housing 2 and insulating tube 3.
A filter circuit assembled with circuit elements such as a capacitor 6 and a capacitor 6 is housed therein. The lead wire 7 connecting the filter circuit to the outside is connected to the opening edge 15 outside the housing 2.
drawn from. Here, the resin 8 is placed inside the insulating cylinder 3.
is injected and solidified to the extent that the inductor 5 is fixed. After the resin 8 has solidified, the bases of the lead wires 7 are tied together with a band, and are pulled out through the through hole 11 in the center of the lid 1, and the connector 9 is connected. Furthermore, the lid 1 is fitted into the opening edge 15 of the housing 2, and the end surface of the insulating tube 3 and the stepped portion 13 of the lid 1 are butted. The rod-shaped protrusion 14 of the lid 1 engages with a ground terminal 4 provided on the housing 2 and the insulating cylinder 3, thereby preventing the lid 1 from rotating. The lid 1 fitted into the opening edge 15 of the casing 2 in this manner is tightened around the opening edge 15 along the outer periphery of the sloped portion 12 of the lid 1.
It is fixed.

As described above, the present invention does not require filling the entire filter circuit element with resin as in the past, but only a part of the element, which reduces the amount of resin used.In addition, the casing 2 can be made smaller, and aluminum foil can be used instead. can be made lightweight and inexpensive. Furthermore, the shielding effect against external noise is sufficient. The lead line has the advantage of always being drawn out at a fixed position.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the lid of an embodiment of the noise filter of the present invention, in which a is a perspective view of the front surface and b is a perspective view of the back surface, and FIG. 2 is a longitudinal sectional view of the embodiment of the noise filter of the present invention. The symbols shown in the diagram are 1: Lid, 2: Housing,
3: Insulating cylinder, 5: Inductor, 6: Capacitor,
7: Lead wire, 8: Resin, 11: Through hole, 1
5: Opening edge.

Claims (1)

[Scope of utility model registration request] A bottomed insulating tube 3 inscribed in a bottomed cylindrical casing 2 made of aluminum is filled with resin only in part of the filter circuit element to fix the filter element, and a lead wire to the outside of the filter element is connected. A disc-shaped lid 1 made of an insulating material and having a sloping part 12 on the upper side of the periphery and a step part 13 on the lower periphery having a through hole for the purpose is fitted into the bottomed insulating cylinder 3, and the fitting part A noise filter formed by caulking the upper edge of the housing 2.